The preference for yew (Taxus baccata) by a red (Sciurus vulgaris) only squirrel population

2015 ◽  
Vol 42 (5) ◽  
pp. 426 ◽  
Author(s):  
Amy Haigh ◽  
Ruth O'Riordan ◽  
Fidelma Butler
Keyword(s):  
Tree Species ◽  
Tree Planting ◽  
Taxus Baccata ◽  
Grey Squirrel ◽  
Red Squirrels ◽  
Coniferous Species ◽  
Coniferous Tree Species ◽  
Term Maintenance ◽  
Grey Squirrels

Context As invasive grey squirrels continue to spread, red only areas are becoming rarer. It has been reported that red squirrels can outcompete greys only in pure coniferous woodland. In areas of sympatry with grey squirrels, there are concerns about red squirrels’ dependence on certain coniferous tree species in light of recent tree diseases. Aims This study aimed to investigate tree selection by red squirrels in an area vulnerable to the spread of the grey squirrel, but currently free of this species. Methods During 2013–14, squirrels were trapped and monitored on a 315-ha managed island, with a woodland characterised by a mixture of deciduous and coniferous species. Radio-tracking revealed that squirrels clustered their activity along a network of yew trees, a preference they showed throughout the year. Trap success was also higher in traps placed on yew trees. Yew and beech were selected most commonly, but squirrels were also observed foraging on other items, such as sycamore flowers and lichen. Squirrels spent 35% of their time foraging, utilising the greatest number of tree species in June (n = 13). In spring, squirrels foraged to a greater extent on the ground than in the trees, and exploited a lower number of tree species. Conclusions There has been little previous data on the use of yew trees by red squirrels, but they have previously been listed as a species that is preferred by red squirrels rather than greys. This study has further emphasised the importance of this tree species to red squirrels. Implications The continued spread of the grey squirrel may lead to red squirrels becoming restricted to areas of intense management such as parks and, accordingly, optimum tree planting is required from the onset for the long-term maintenance of red squirrels. With recent concern about the disease vulnerability of other coniferous species, this study emphasises the relative importance of yew and other tree species in the distribution of red squirrels.

scholarly journals Natural strongholds for red squirrel conservation in Scotland

2021 ◽  
Vol 43 ◽  
pp. 93-108
Author(s):  
Andrew Slade ◽  
Andy White ◽  
Kenny Kortland ◽  
Peter W. W. Lurz
Keyword(s):  
Management Practice ◽  
Management Policy ◽  
Sciurus Carolinensis ◽  
Red Squirrel ◽  
Grey Squirrel ◽  
Case Scenario ◽  
Red Squirrels ◽  
Worst Case ◽  
Standard Management ◽  
Grey Squirrels

The Eurasian Red Squirrel (Sciurus vulgaris) is under threat from the invasive North American eastern Grey Squirrel (Sciurus carolinensis) with 80% of the remaining red squirrel populations in the British Isles found in Scotland. In this study we develop a spatially explicit mathematical model of the red and grey squirrel system and use it to assess the population viability of red squirrels across Scotland. In particular, we aim to identify existing forests – natural strongholds for red squirrels – that can successfully support red squirrels under UK Forestry Standard management and protect them from potential disease-mediated competition from grey squirrels. Our model results indicate that if current levels of grey squirrel control, which restrict or reduce the distribution of grey squirrels, are continued then there will be large expanses of forests in northern Scotland that support viable red squirrel populations. Model results that represent (hypothetical) scenarios where grey squirrel control no longer occurred indicated that grey squirrel range expansion and the process of red squirrel replacement would be slow. Model results for an assumed worst-case scenario where grey squirrels have expanded to all regions in Scotland identified forest regions – denoted natural strongholds – that could currently support red squirrels under UK Forestry Standard management practice. The results will be used to inform forest management policy and support a strategic review of red squirrel management by land management agencies and other stakeholders.

scholarly journals Native and invasive squirrels show different behavioural responses to scent of a shared native predator

2020 ◽  
Vol 7 (2) ◽  
pp. 191841 ◽  
Author(s):  
Joshua P. Twining ◽  
W. Ian Montgomery ◽  
Lily Price ◽  
Hansjoerg P. Kunc ◽  
David G. Tosh
Keyword(s):  
Species Interactions ◽  
Native Species ◽  
Prey Species ◽  
Red Squirrel ◽  
Pine Marten ◽  
Grey Squirrel ◽  
Red Squirrels ◽  
Behavioural Responses ◽  
Grey Squirrels ◽  
Native Predator

Invasive species pose a serious threat to native species. In Europe, invasive grey squirrels ( Sciurus carolinensis ) have replaced native red squirrels ( Sciurus vulgaris ) in locations across Britain, Ireland and Italy. The European pine marten ( Martes martes ) can reverse the replacement of red squirrels by grey squirrels, but the underlying mechanism of how pine martens suppress grey squirrels is little understood. Research suggests the reversal process is driven by direct predation, but why the native red squirrel may be less susceptible than the invasive grey squirrel to predation by a commonly shared native predator, is unknown. A behavioural difference may exist with the native sciurid being more effective at avoiding predation by the pine marten with which they have a shared evolutionary history. In mammals, olfactory cues are used by prey species to avoid predators. To test whether anti-predator responses differ between the native red squirrel and the invasive grey squirrel, we exposed both species to scent cues of a shared native predator and quantified the responses of the two squirrel species. Red squirrels responded to pine marten scent by avoiding the feeder, increasing their vigilance and decreasing their feeding activity. By contrast, grey squirrels did not show any anti-predator behaviours in response to the scent of pine marten. Thus, differences in behavioural responses to a shared native predator may assist in explaining differing outcomes of species interactions between native and invasive prey species depending on the presence, abundance and exposure to native predators.

scholarly journals Impact of long and short-term conservation periods on structure of English yew (Taxus baccata L.) in Arasbaran forests, Iran

2019 ◽  
Vol 65 (No. 7) ◽  
pp. 272-282 ◽  
Author(s):  
Sajad Ghanbari ◽  
Kiomars Sefidi ◽  
Matthew Aghai
Keyword(s):  
Tree Species ◽  
Stand Structure ◽  
Structural Characteristics ◽  
Conservation Status ◽  
Taxus Baccata ◽  
Short Term ◽  
Species Identity ◽  
Reference Tree ◽  
Evans Index

Yew (Taxus baccata L.) is one of the most important and threatened tree species in the Arasbaran region of northwestern Iran. To understand the natural stand structure of yew forests to inform forest management, we assessed the structural characteristics and composition of yew communities using the nearest neighbour and full callipering method at three sites with different conservation histories. Within a one-hectare sampling area, tree species identity, diameter, height, and crown diameter were measured. In each of these sampling areas, 56 sample points were surveyed in a 25 m × 25 m grid for tree species identity, diameter, height, and distance from reference to neighbour trees. To quantify the structural characteristics in areas of different conservation status, some indices were calculated including mingling, distance between reference tree and its nearest neighbouring trees, diameter and height differentiation, uniform angle, and Clark-Evans index. Results revealed that four species – hornbeam (68%), maple (8%), yew (7%), and oak (5.2%) – composed 88% of the tree species. The majority of trees had a short distance (2–3 m) between neighbours. The mean diameter differentiation index for long-term and short-term conservation areas was 0.59 and 0.06, respectively. The uniform angle index showed that there was no class value = “1” at all three sites. In the long-term enclosed area, Clark-Evans index was 1.18. In short-term enclosed areas, it was less than 1 (0.82). At all sites, yew trees were in the least vital class. We conclude that enclosing affects the yew stand structure, specifically in long-term periods of enclosure.

Indoor storage time affects the quality and quantity of volatile monoterpenes emitted from softwood timber

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Riina Muilu-Mäkelä ◽  
Petri Kilpeläinen ◽  
Veikko Kitunen ◽  
Anni Harju ◽  
Martti Venäläinen ◽  
...  
Keyword(s):  
Scots Pine ◽  
Tree Species ◽  
Solid Phase ◽  
Construction Material ◽  
Test Chamber ◽  
Acoustic Properties ◽  
Indoor Environmental Quality ◽  
Coniferous Tree Species ◽  
One Year

Abstract Wood as a construction material affects indoor environmental quality by moisture buffering, good acoustic properties and by the wood specific volatile organic compounds (VOC). The most abundant VOCs of soft wood are volatile monoterpenes (VM) giving the typical odor of wood. In the present study, long-term VM emissions of wood of two northern coniferous tree species, Scots pine and Norway spruce were observed regularly during one year in storage. Fresh and dried 20 cm long wood blocks were placed in a test chamber; VMs were collected with the solid phase micro extraction fiber and analyzed by gas chromatography-mass spectrometer. Average emission of nine different VMs, α- and β-pinene, 3-carene, limonene, terpinolene, myrcene, camphene, ortho-cymene and ƴ-terpinene, decreased 68–87% during one-year long storage. Moisture content (MC), knots, tree species and tree individual affected the VM emissions from wood. When a certain level of MC (12%) was reached, the VM levels decreased, but the method of drying (industrial or dried in storage) did not affect the amount of released VMs. Rehydration and dehydration increased and decreased VM emissions, respectively. Moreover, two of the eight Scots pine heartwood planks contained almost no 3-carene while being the most abundant monoterpene in the others.

scholarly journals Disease threats posed by alien species: the role of a poxvirus in the decline of the native red squirrel in Britain

2005 ◽  
Vol 134 (3) ◽  
pp. 521-533 ◽  
Author(s):  
S. P. RUSHTON ◽  
P. W. W. LURZ ◽  
J. GURNELL ◽  
P. NETTLETON ◽  
C. BRUEMMER ◽  
...  
Keyword(s):  
Population Control ◽  
Disease Model ◽  
Red Squirrel ◽  
Grey Squirrel ◽  
Red Squirrels ◽  
Contact Rates ◽  
The United Kingdom ◽  
Model Predictions ◽  
Grey Squirrels

Red squirrels are declining in the United Kingdom. Competition from, and squirrel poxvirus (SQPV) disease carried by, grey squirrels are assumed to be determining the decline. We analyse the incidence of disease and changes in distribution of the two species in Cumbria, from 1993 to 2003 and compare these to the predictions of an individual-based (IB) spatially explicit disease model simulating the dynamics of both squirrel species and SQPV in the landscape. Grey squirrels increased whilst red squirrels declined over 10 years. The incidence of disease in red squirrels was related to the time since grey squirrels arrived in the landscape. Analysis of rates of decline in red squirrel populations in other areas showed that declines are 17–25 times higher in regions where SQPV is present in grey squirrel populations than in those where it is not. The IB model predicted spatial overlap of 3–4 years between the species that was also observed in the field. The model predictions matched the observed data best when contact rates and rates of infection between the two species were low. The model predicted that a grey squirrel population control of >60% effective kill was needed to stop the decline in red squirrel populations in Cumbria.

Responses of soil dissolved organic matter to long-term plantations of three coniferous tree species

Geoderma ◽  
2012 ◽  
Vol 170 ◽  
pp. 136-143 ◽  
Author(s):  
Shunbao Lu ◽  
Chengrong Chen ◽  
Xiaoqi Zhou ◽  
Zhihong Xu ◽  
Gary Bacon ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Tree Species ◽  
Coniferous Tree ◽  
Coniferous Tree Species

scholarly journals An Opportunistic Assessment of the Impact of Squirrelpox Disease Outbreaks upon a Red Squirrel Population Sympatric with Grey Squirrels in Wales

Animals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 99
Author(s):  
Craig M. Shuttleworth ◽  
David Everest ◽  
Paul Holmes ◽  
Suzi Bell ◽  
Rachel Cripps
Keyword(s):  
Survival Rates ◽  
Disease Outbreaks ◽  
Sciurus Carolinensis ◽  
Red Squirrel ◽  
Grey Squirrel ◽  
Red Squirrels ◽  
Local Survival ◽  
Temporal And Spatial ◽  
The Impact ◽  
Grey Squirrels

Native red squirrels (Sciurus vulgaris) persisted in the coastal mainland woodlands of northern Gwynedd whilst sympatric with an invasive grey squirrel (Sciurus carolinensis) population suppressed by culling. Squirrelpox disease in the red squirrel population was recorded in 2017 and 2020/21. An autumn 2020 outbreak was associated with only 17.4% of animals caught and marked in the preceding June known to be present in March 2021. Despite an opportunistic data collection lacking the rigour of empirical experimental design, we observed low local survival rates similar to previously published accounts reported during major squirrelpox outbreaks. The use of a conservation dog to detect red squirrel carcasses resulted in positive detection and confirmation of a temporal and spatial expansion of one disease outbreak. The study is the first in Wales to use conservation dogs and the findings reinforce the vital strategic importance of geographical isolation reducing sympatry of red with grey squirrels in European regions where the introduced congener is a source of the squirrelpox infection.

Efficacious long-term maintenance therapy with pantoprazole (PAN) in patients with Zollinger-Ellison syndrome

2001 ◽  
Vol 120 (5) ◽  
pp. A613-A613
Author(s):  
P BORNMAN ◽  
K RADEBOLD ◽  
H DEBAERE ◽  
L VENTER ◽  
H HEINZE ◽  
...  
Keyword(s):  
Maintenance Therapy ◽  
Zollinger Ellison Syndrome ◽  
Term Maintenance

Manipulating group reinforcement schedules: Problems in long term maintenance of treatment effects

1976 ◽  
Author(s):  
Hyman Hops ◽  
Charles R. Greenwood ◽  
Hill M. Walker
Keyword(s):  
Treatment Effects ◽  
Reinforcement Schedules ◽  
Term Maintenance
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